add ready and healthy probe endpoints

api/metrics.go

@@ -0,0 +1,73 @@
+package api
+
+import (
+	"runtime"
+
+	"github.com/aptly-dev/aptly/aptly"
+	"github.com/gin-gonic/gin"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	apiRequestsInFlightGauge = promauto.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "aptly_api_http_requests_in_flight",
+			Help: "Number of concurrent HTTP api requests currently handled.",
+		},
+		[]string{"method", "path"},
+	)
+	apiRequestsTotalCounter = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "aptly_api_http_requests_total",
+			Help: "Total number of api requests.",
+		},
+		[]string{"code", "method", "path"},
+	)
+	apiRequestSizeSummary = promauto.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Name: "aptly_api_http_request_size_bytes",
+			Help: "Api HTTP request size in bytes.",
+		},
+		[]string{"code", "method", "path"},
+	)
+	apiResponseSizeSummary = promauto.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Name: "aptly_api_http_response_size_bytes",
+			Help: "Api HTTP response size in bytes.",
+		},
+		[]string{"code", "method", "path"},
+	)
+	apiRequestsDurationSummary = promauto.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Name: "aptly_api_http_request_duration_seconds",
+			Help: "Duration of api requests in seconds.",
+		},
+		[]string{"code", "method", "path"},
+	)
+	apiVersionGauge = promauto.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "aptly_build_info",
+			Help: "Metric with a constant '1' value labeled by version and goversion from which aptly was built.",
+		},
+		[]string{"version", "goversion"},
+	)
+)
+
+type metricsCollectorRegistrar struct {
+	hasRegistered bool
+}
+
+func (r *metricsCollectorRegistrar) Register(router *gin.Engine) {
+	if !r.hasRegistered {
+		apiVersionGauge.WithLabelValues(aptly.Version, runtime.Version()).Set(1)
+		router.Use(instrumentHandlerInFlight(apiRequestsInFlightGauge, getBasePath))
+		router.Use(instrumentHandlerCounter(apiRequestsTotalCounter, getBasePath))
+		router.Use(instrumentHandlerRequestSize(apiRequestSizeSummary, getBasePath))
+		router.Use(instrumentHandlerResponseSize(apiResponseSizeSummary, getBasePath))
+		router.Use(instrumentHandlerDuration(apiRequestsDurationSummary, getBasePath))
+		r.hasRegistered = true
+	}
+}
+
+var MetricsCollectorRegistrar = metricsCollectorRegistrar{hasRegistered: false}